I noticed in my NUC8i3 BIOS that, when setting options for enabling/disabling USB ports, the F1 help specifies that disabling the ports will still allow a keyboard to work. I'd like to disable USB while in general use as it's for audio applications and I'd like to minimise electrical noise and load as much as possible. The NUC is running Roon ROCK OS headless so keyboard isn't needed for everyday operation. I would only need the keyboard now and again to go into BIOS and need to check this will still work with F2 on startup if I disable USB.
You should leave Legacy USB support enabled. If the Legacy USB support is enabled, USB keyboard/mouse can be used during POST and you will be able enter bios and make changes. If you have disable some USB ports in bios, they will be disabled once you boot into Windows.
Thanks, that's great.
I'm not using Windows, as ROCK is a custom Linux OS. Can I assume that if I disable USB in BIOS that it will only be available during POST (assuming I leave Legacy USB support checked) and powered down after this so that it's off regardless of the OS in use?